SQL errors when uninstalling the plugin

[C-Duv]

When uninstalling v3.0.4b2 of the plugin, sql-errors.log is filled with SQL errors complaining about tables it cannot find:

*** MySQL query error:
SQL: DROP TABLE `glpi_plugin_room_rooms_computers`
Error: Unknown table 'glpi_plugin_room_rooms_computers'
Backtrace :
plugins\room\hook.php:355                          
inc\plugin.class.php:639                           plugin_room_uninstall()
:                                                  Plugin->uninstall()
front\plugin.form.php:49                           call_user_func()

Tables are:

• glpi_plugin_room_rooms_computers
• glpi_plugin_room_roomtypes
• glpi_plugin_room_roomaccessconds
• glpi_plugin_room_dropdown1s
• glpi_plugin_room_rooms

[C-Duv]

Fixed by PR #16.